organic compounds
Ethyl 4,9-dimethyl-9H-carbazole-3-carboxylate
aDokuz Eylül University, Faculty of Arts and Sciences, Department of Chemistry, Tınaztepe, 35160 Buca, İzmir, Turkey, bAksaray University, Department of Physics, 68100, Aksaray, Turkey, cDepartment of Physics, Sakarya University, 54187 Esentepe, Sakarya, Turkey, and dHacettepe University, Department of Physics, 06800 Beytepe, Ankara, Turkey
*Correspondence e-mail: merzifon@hacettepe.edu.tr
In the title compound, C17H17NO2, the carbazole skeleton includes an ethoxycarbonyl group at the 3-position. The indole three-ring system is almost planar [maximum deviation = 0.065 (2) Å], and the ethyl ester group is inclined to its mean plane by 15.48 (2)°. In the crystal, there are π–π stacking interactions between parallel benzene rings and between parallel benzene and pyrrole rings of adjacent molecules [centroid–centroid distances = 3.9473 (8) and 3.7758 (8) Å, respectively]. Weak C—H⋯π interactions are also present.
CCDC reference: 984122
Related literature
For the first isolation of carbazole from coal tar, see: Graebe & Glazer (1872). For the isolation of murrayanine, the first report of a naturally occurring carbazole alkaloid, see: Chakraborty et al. (1965). For the intriguing structural features and promising biological activities exhibited by many carbazole see: Chakraborty (1993). For the syntheses of pyridocarbazoles, see: Karmakar et al. (1991). For related structures, see: Hökelek et al. (1994); Patır et al. (1997). For bond-length data, see: Allen et al. (1987).
Experimental
Crystal data
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Data collection: APEX2 (Bruker, 2007); cell SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012) and PLATON (Spek, 2009).
Supporting information
CCDC reference: 984122
10.1107/S1600536814002098/su2693sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536814002098/su2693Isup2.hkl
Supporting information file. DOI: 10.1107/S1600536814002098/su2693Isup3.cml
A solution of ethyl 4-methyl-9H-carbazole-3-carboxylate (2.50 g, 10 mmol), potassium hydroxide (1.70 g, 30 mmol) and methyl iodide (1.25 ml, 20 mmol) in acetone (100 ml) was stirred at 273 K for 2 h, and then acidified with HCl (6N). The aqueous layer was extracted with dichloromethane. The combined organic phases were dried with magnesium sulfate, filtered, and the solvents were evaporated. The residue was purified by
using silica gel, hexane/ethyl acetate (1:1). After the solvent was evaporated, the crude product was recrystallized from methanol (yield 87%, M.p. 383 K), giving colourless prismatic crystals.The C-bound H-atoms were positioned geometrically with C—H = 0.93, 0.97 and 0.96 Å, for aromatic, methylene and methyl H-atoms, respectively, and constrained to ride on their parent atoms, with Uiso(H) = k × Ueq(C), where k = 1.5 for methyl H-atoms and = 1.2 for other H-atoms.
Data collection: APEX2 (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: WinGX (Farrugia, 2012) and PLATON (Spek, 2009).Fig. 1. The molecular structure of the title molecule, with atom labelling. Displacement ellipsoids are drawn at the 50% probability level. | |
Fig. 2. A view of the crystal packing of the title compound [H-atoms have been omitted for clarity]. |
C17H17NO2 | F(000) = 1136 |
Mr = 267.32 | Dx = 1.287 Mg m−3 |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 9733 reflections |
a = 14.5228 (5) Å | θ = 2.5–28.6° |
b = 12.4663 (4) Å | µ = 0.08 mm−1 |
c = 15.2354 (5) Å | T = 296 K |
V = 2758.30 (16) Å3 | Prism, colourless |
Z = 8 | 0.43 × 0.35 × 0.25 mm |
Bruker SMART BREEZE CCD diffractometer | 2798 independent reflections |
Radiation source: fine-focus sealed tube | 2358 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.041 |
φ and ω scans | θmax = 26.4°, θmin = 2.5° |
Absorption correction: multi-scan (SADABS; Bruker, 2007) | h = −18→18 |
Tmin = 0.965, Tmax = 0.979 | k = −15→15 |
61052 measured reflections | l = −19→19 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.049 | H-atom parameters constrained |
wR(F2) = 0.133 | w = 1/[σ2(Fo2) + (0.0716P)2 + 0.6943P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
2798 reflections | Δρmax = 0.23 e Å−3 |
185 parameters | Δρmin = −0.18 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0071 (10) |
C17H17NO2 | V = 2758.30 (16) Å3 |
Mr = 267.32 | Z = 8 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 14.5228 (5) Å | µ = 0.08 mm−1 |
b = 12.4663 (4) Å | T = 296 K |
c = 15.2354 (5) Å | 0.43 × 0.35 × 0.25 mm |
Bruker SMART BREEZE CCD diffractometer | 2798 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2007) | 2358 reflections with I > 2σ(I) |
Tmin = 0.965, Tmax = 0.979 | Rint = 0.041 |
61052 measured reflections |
R[F2 > 2σ(F2)] = 0.049 | 0 restraints |
wR(F2) = 0.133 | H-atom parameters constrained |
S = 1.07 | Δρmax = 0.23 e Å−3 |
2798 reflections | Δρmin = −0.18 e Å−3 |
185 parameters |
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes. |
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.41026 (9) | 0.81153 (11) | 0.06716 (8) | 0.0672 (4) | |
O2 | 0.46532 (8) | 0.86264 (9) | −0.06240 (7) | 0.0529 (3) | |
C1 | 0.62278 (10) | 0.60151 (12) | −0.10399 (9) | 0.0442 (4) | |
H1 | 0.6469 | 0.5902 | −0.1598 | 0.053* | |
C2 | 0.56446 (10) | 0.68566 (12) | −0.08727 (9) | 0.0430 (3) | |
H2 | 0.5484 | 0.7312 | −0.1331 | 0.052* | |
C3 | 0.52798 (9) | 0.70562 (11) | −0.00294 (9) | 0.0396 (3) | |
C4 | 0.55188 (9) | 0.63966 (12) | 0.06812 (9) | 0.0392 (3) | |
C4A | 0.60974 (9) | 0.55202 (11) | 0.05131 (8) | 0.0376 (3) | |
C5 | 0.63676 (11) | 0.43336 (14) | 0.19289 (10) | 0.0503 (4) | |
H5 | 0.6028 | 0.4749 | 0.2320 | 0.060* | |
C5A | 0.64528 (9) | 0.46499 (12) | 0.10518 (9) | 0.0404 (3) | |
C6 | 0.67876 (12) | 0.34056 (15) | 0.22115 (11) | 0.0585 (4) | |
H6 | 0.6730 | 0.3200 | 0.2796 | 0.070* | |
C7 | 0.72949 (12) | 0.27711 (15) | 0.16397 (12) | 0.0585 (4) | |
H7 | 0.7568 | 0.2146 | 0.1847 | 0.070* | |
C8 | 0.74011 (11) | 0.30520 (13) | 0.07687 (11) | 0.0507 (4) | |
H8 | 0.7744 | 0.2630 | 0.0386 | 0.061* | |
C8A | 0.69762 (9) | 0.39910 (12) | 0.04852 (10) | 0.0419 (3) | |
N9 | 0.69734 (8) | 0.44270 (10) | −0.03478 (8) | 0.0430 (3) | |
C9A | 0.64444 (9) | 0.53372 (11) | −0.03426 (9) | 0.0392 (3) | |
C10 | 0.74717 (13) | 0.40054 (15) | −0.10959 (11) | 0.0575 (4) | |
H10A | 0.7397 | 0.3241 | −0.1120 | 0.086* | |
H10B | 0.8114 | 0.4176 | −0.1039 | 0.086* | |
H10C | 0.7235 | 0.4320 | −0.1625 | 0.086* | |
C11 | 0.52039 (12) | 0.66026 (15) | 0.16070 (10) | 0.0564 (4) | |
H11A | 0.5690 | 0.6424 | 0.2008 | 0.085* | |
H11B | 0.4674 | 0.6168 | 0.1732 | 0.085* | |
H11C | 0.5047 | 0.7346 | 0.1672 | 0.085* | |
C12 | 0.46242 (10) | 0.79659 (12) | 0.00684 (9) | 0.0441 (3) | |
C13 | 0.39819 (11) | 0.94836 (13) | −0.06466 (11) | 0.0515 (4) | |
H13A | 0.3366 | 0.9200 | −0.0567 | 0.062* | |
H13B | 0.4104 | 0.9999 | −0.0184 | 0.062* | |
C14 | 0.40701 (16) | 0.99994 (19) | −0.15226 (13) | 0.0778 (6) | |
H14A | 0.3947 | 0.9480 | −0.1973 | 0.117* | |
H14B | 0.4684 | 1.0273 | −0.1592 | 0.117* | |
H14C | 0.3637 | 1.0578 | −0.1568 | 0.117* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0694 (8) | 0.0763 (9) | 0.0559 (7) | 0.0237 (7) | 0.0186 (6) | 0.0033 (6) |
O2 | 0.0516 (6) | 0.0491 (7) | 0.0579 (7) | 0.0120 (5) | 0.0104 (5) | 0.0057 (5) |
C1 | 0.0473 (8) | 0.0509 (9) | 0.0345 (7) | 0.0007 (7) | 0.0044 (5) | −0.0033 (6) |
C2 | 0.0446 (7) | 0.0460 (8) | 0.0383 (7) | −0.0001 (6) | −0.0004 (6) | 0.0006 (6) |
C3 | 0.0356 (7) | 0.0423 (8) | 0.0408 (7) | −0.0030 (6) | 0.0010 (5) | −0.0033 (6) |
C4 | 0.0352 (6) | 0.0435 (8) | 0.0390 (7) | −0.0055 (6) | 0.0030 (5) | −0.0036 (6) |
C4A | 0.0334 (6) | 0.0419 (8) | 0.0374 (7) | −0.0071 (6) | 0.0005 (5) | −0.0025 (5) |
C5 | 0.0458 (8) | 0.0594 (10) | 0.0458 (8) | −0.0044 (7) | 0.0038 (6) | 0.0060 (7) |
C5A | 0.0338 (6) | 0.0436 (8) | 0.0437 (7) | −0.0063 (6) | −0.0006 (5) | 0.0001 (6) |
C6 | 0.0559 (9) | 0.0665 (11) | 0.0532 (9) | −0.0073 (8) | −0.0007 (7) | 0.0171 (8) |
C7 | 0.0534 (9) | 0.0508 (10) | 0.0712 (11) | −0.0027 (8) | −0.0062 (8) | 0.0153 (8) |
C8 | 0.0441 (8) | 0.0451 (9) | 0.0628 (9) | −0.0004 (6) | −0.0019 (7) | 0.0011 (7) |
C8A | 0.0355 (7) | 0.0426 (8) | 0.0476 (7) | −0.0064 (6) | −0.0019 (5) | −0.0014 (6) |
N9 | 0.0436 (7) | 0.0442 (7) | 0.0413 (6) | 0.0027 (5) | 0.0027 (5) | −0.0040 (5) |
C9A | 0.0358 (7) | 0.0416 (8) | 0.0401 (7) | −0.0031 (6) | 0.0009 (5) | −0.0049 (6) |
C10 | 0.0607 (10) | 0.0618 (11) | 0.0501 (9) | 0.0137 (8) | 0.0077 (7) | −0.0093 (8) |
C11 | 0.0616 (10) | 0.0654 (11) | 0.0422 (8) | 0.0109 (8) | 0.0111 (7) | −0.0006 (7) |
C12 | 0.0407 (7) | 0.0477 (8) | 0.0441 (7) | −0.0008 (6) | 0.0009 (6) | −0.0034 (6) |
C13 | 0.0504 (9) | 0.0475 (9) | 0.0567 (9) | 0.0118 (7) | 0.0059 (7) | −0.0034 (7) |
C14 | 0.0905 (15) | 0.0754 (14) | 0.0675 (12) | 0.0381 (12) | 0.0201 (10) | 0.0156 (10) |
O1—C12 | 1.2054 (18) | C8—C7 | 1.381 (2) |
O2—C12 | 1.3388 (18) | C8—H8 | 0.9300 |
O2—C13 | 1.4469 (18) | C8A—C8 | 1.392 (2) |
C1—H1 | 0.9300 | N9—C8A | 1.3805 (19) |
C2—C1 | 1.372 (2) | N9—C9A | 1.3704 (18) |
C2—H2 | 0.9300 | N9—C10 | 1.4488 (19) |
C3—C2 | 1.4119 (19) | C9A—C1 | 1.393 (2) |
C3—C12 | 1.488 (2) | C10—H10A | 0.9600 |
C4—C3 | 1.403 (2) | C10—H10B | 0.9600 |
C4—C11 | 1.5049 (19) | C10—H10C | 0.9600 |
C4A—C4 | 1.402 (2) | C11—H11A | 0.9600 |
C4A—C5A | 1.455 (2) | C11—H11B | 0.9600 |
C4A—C9A | 1.4162 (18) | C11—H11C | 0.9600 |
C5—C6 | 1.377 (2) | C13—C14 | 1.487 (2) |
C5—H5 | 0.9300 | C13—H13A | 0.9700 |
C5A—C5 | 1.399 (2) | C13—H13B | 0.9700 |
C5A—C8A | 1.413 (2) | C14—H14A | 0.9600 |
C6—C7 | 1.388 (3) | C14—H14B | 0.9600 |
C6—H6 | 0.9300 | C14—H14C | 0.9600 |
C7—H7 | 0.9300 | ||
C12—O2—C13 | 116.86 (12) | C8A—N9—C10 | 125.37 (13) |
C2—C1—C9A | 117.48 (13) | C9A—N9—C8A | 108.81 (11) |
C2—C1—H1 | 121.3 | C9A—N9—C10 | 125.80 (13) |
C9A—C1—H1 | 121.3 | N9—C9A—C1 | 128.64 (12) |
C1—C2—C3 | 122.36 (13) | N9—C9A—C4A | 109.76 (12) |
C1—C2—H2 | 118.8 | C1—C9A—C4A | 121.59 (13) |
C3—C2—H2 | 118.8 | N9—C10—H10A | 109.5 |
C2—C3—C12 | 117.74 (13) | N9—C10—H10B | 109.5 |
C4—C3—C2 | 120.40 (13) | N9—C10—H10C | 109.5 |
C4—C3—C12 | 121.85 (12) | H10A—C10—H10B | 109.5 |
C3—C4—C11 | 123.23 (13) | H10C—C10—H10A | 109.5 |
C4A—C4—C3 | 117.65 (12) | H10C—C10—H10B | 109.5 |
C4A—C4—C11 | 119.11 (13) | C4—C11—H11A | 109.5 |
C4—C4A—C5A | 133.68 (12) | C4—C11—H11B | 109.5 |
C4—C4A—C9A | 120.47 (13) | C4—C11—H11C | 109.5 |
C9A—C4A—C5A | 105.84 (12) | H11B—C11—H11A | 109.5 |
C5A—C5—H5 | 120.1 | H11B—C11—H11C | 109.5 |
C6—C5—C5A | 119.77 (15) | H11C—C11—H11A | 109.5 |
C6—C5—H5 | 120.1 | O1—C12—O2 | 121.70 (14) |
C5—C5A—C4A | 135.87 (14) | O1—C12—C3 | 126.58 (14) |
C5—C5A—C8A | 117.86 (14) | O2—C12—C3 | 111.69 (12) |
C8A—C5A—C4A | 106.23 (12) | O2—C13—C14 | 106.43 (13) |
C5—C6—C7 | 121.17 (15) | O2—C13—H13A | 110.4 |
C5—C6—H6 | 119.4 | O2—C13—H13B | 110.4 |
C7—C6—H6 | 119.4 | C14—C13—H13A | 110.4 |
C8—C7—C6 | 121.18 (16) | C14—C13—H13B | 110.4 |
C8—C7—H7 | 119.4 | H13B—C13—H13A | 108.6 |
C6—C7—H7 | 119.4 | C13—C14—H14A | 109.5 |
C7—C8—C8A | 117.51 (16) | C13—C14—H14B | 109.5 |
C7—C8—H8 | 121.2 | C13—C14—H14C | 109.5 |
C8A—C8—H8 | 121.2 | H14B—C14—H14A | 109.5 |
N9—C8A—C5A | 109.34 (13) | H14B—C14—H14C | 109.5 |
N9—C8A—C8 | 128.14 (14) | H14C—C14—H14A | 109.5 |
C8—C8A—C5A | 122.52 (14) | ||
C13—O2—C12—O1 | −4.5 (2) | C5A—C4A—C9A—N9 | 0.13 (15) |
C13—O2—C12—C3 | 174.05 (12) | C5A—C4A—C9A—C1 | 178.99 (13) |
C12—O2—C13—C14 | −172.34 (16) | C5A—C5—C6—C7 | −0.2 (2) |
C3—C2—C1—C9A | 1.0 (2) | C4A—C5A—C5—C6 | 177.19 (15) |
C4—C3—C2—C1 | 1.0 (2) | C8A—C5A—C5—C6 | 0.0 (2) |
C12—C3—C2—C1 | −177.59 (13) | C4A—C5A—C8A—N9 | 1.47 (15) |
C2—C3—C12—O1 | 162.94 (16) | C4A—C5A—C8A—C8 | −177.90 (13) |
C2—C3—C12—O2 | −15.50 (18) | C5—C5A—C8A—N9 | 179.47 (13) |
C4—C3—C12—O1 | −15.7 (2) | C5—C5A—C8A—C8 | 0.1 (2) |
C4—C3—C12—O2 | 165.90 (13) | C5—C6—C7—C8 | 0.4 (3) |
C4A—C4—C3—C2 | −2.4 (2) | C8A—C8—C7—C6 | −0.4 (2) |
C4A—C4—C3—C12 | 176.15 (12) | N9—C8A—C8—C7 | −179.14 (15) |
C11—C4—C3—C2 | 176.05 (14) | C5A—C8A—C8—C7 | 0.1 (2) |
C11—C4—C3—C12 | −5.4 (2) | C9A—N9—C8A—C5A | −1.42 (15) |
C5A—C4A—C4—C3 | −176.61 (14) | C9A—N9—C8A—C8 | 177.90 (14) |
C5A—C4A—C4—C11 | 4.9 (2) | C10—N9—C8A—C5A | 176.89 (14) |
C9A—C4A—C4—C3 | 1.83 (19) | C10—N9—C8A—C8 | −3.8 (2) |
C9A—C4A—C4—C11 | −176.69 (13) | C8A—N9—C9A—C1 | −177.97 (14) |
C4—C4A—C5A—C5 | 0.2 (3) | C8A—N9—C9A—C4A | 0.79 (15) |
C4—C4A—C5A—C8A | 177.64 (14) | C10—N9—C9A—C1 | 3.7 (2) |
C9A—C4A—C5A—C5 | −178.42 (16) | C10—N9—C9A—C4A | −177.52 (14) |
C9A—C4A—C5A—C8A | −0.96 (14) | N9—C9A—C1—C2 | 177.05 (14) |
C4—C4A—C9A—N9 | −178.70 (12) | C4A—C9A—C1—C2 | −1.6 (2) |
C4—C4A—C9A—C1 | 0.2 (2) |
Cg1, Cg2 and Cg3 are the centroids of rings N9/C8A/C5A/C4A/C9A, C1–C4/C4A/C9A, and C5/C5A/C8A/C8/C7/C6, respectively. |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8···Cg1i | 0.93 | 2.83 | 3.7091 (17) | 159 |
C13—H13A···Cg2ii | 0.97 | 2.91 | 3.6381 (17) | 133 |
C14—H14C···Cg3ii | 0.96 | 2.73 | 3.580 (2) | 149 |
Symmetry codes: (i) x, −y−3/2, z−1/2; (ii) −x, y+1/2, −z+3/2. |
Cg1, Cg2 and Cg3 are the centroids of rings N9/C8A/C5A/C4A/C9A, C1–C4/C4A/C9A, and C5/C5A/C8A/C8/C7/C6, respectively. |
D—H···A | D—H | H···A | D···A | D—H···A |
C8—H8···Cg1i | 0.93 | 2.83 | 3.7091 (17) | 159 |
C13—H13A···Cg2ii | 0.97 | 2.91 | 3.6381 (17) | 133 |
C14—H14C···Cg3ii | 0.96 | 2.73 | 3.580 (2) | 149 |
Symmetry codes: (i) x, −y−3/2, z−1/2; (ii) −x, y+1/2, −z+3/2. |
Acknowledgements
The authors acknowledge the Aksaray University, Science and Technology Application and Research Center, Aksaray, Turkey, for the use of the Bruker SMART BREEZE CCD diffractometer (purchased under grant No. 2010K120480 of the State of Planning Organization).
References
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Carbazole was firstly isolated from coal tar many years ago (Graebe & Glazer, 1872). The isolation of murrayanine was the first report of a naturally occurring carbazole alkaloid (Chakraborty et al., 1965). Since then there has been a strong interest in this area by chemists and biologists due to the intriguing structural features and promising biological activities exhibited by many carbazole alkaloids (Chakraborty, 1993). Most carbazole alkaloids have been isolated from the taxonomically related higher plants of the genus Murraya, Glycosmis and Clausena from the family Rutaceae. The genus Murraya represents the richest source of carbazole alkaloids from terrestrial plants. The title compound was used as a precursor compound for the syntheses of pyridocarbazoles (Karmakar et al., 1991) and we report herein on its crystal structure.
The molecule of the title compound, Fig. 1, contains a carbazole skeleton with an ethoxycarbonyl group at the 3 position. The bond lengths are close to standard values (Allen et al., 1987) and generally agree with those in previously reported compounds (Hökelek et al., 1994; Patır et al., 1997). In all structures atom N9 is substituted.
An examination of the deviations from the least-squares planes through individual rings shows that rings A (C1—C4/C4a/c9a), B (C4a/C5a/C8a/N9/C9a) and C (C5a/C5—C8/C8a) are nearly coplanar [with a maximum deviation of 0.065 (2) Å for atom C7] with dihedral angles of A/B = 2.41 (4) °, A/C = 4.01 (4) ° and B/C = 1.63 (5) °. Atoms C10, C11 and C12 are displaced by -0.059 (2), -0.092 (2) and 0.079 (2) Å from the adjacent ring planes.
In the crystal, π–π contacts between the benzene rings and between the benzene and pyrrole rings, Cg1···Cg1i and Cg2···Cg1i [symmetry code: (i) 1 - x, - y, 1 - z, where Cg1 and Cg2 are the centroids of the rings A (C1—C4/C4a/C9a) and B (C4a/C5a/C8a/N9/C9a), respectively] stabilize the crystal structure, with centroid-centroid distances of 3.9473 (8) and 3.7758 (8) Å. The weak C—H···π interactions (Table 1) may be further effective in the stabilization of the crystal structure.